Re: green / blue screen tips needed

Dave,

Knowing what format you're actually recording on is important. You mention
an ENG camera, but is that Beta SP that uses a 4:2:2 compression scheme, or
is in some flavor of DV that's compressing to 4:1:1 or even 4:1:0? That's a
key factor as to how much "wiggle room" you have to pull clean edges.

Secondly, what software is being used for keying? Assuming something like
After Effects Pro and a knowledgable user, you shouldn't have any problems.
Uniformity of keying color is more important than actual exposure, but the
closer to mid range you can get the better.

For your exterior work, I hope you're not trying to work with anything
larger than a 12' X 12' screen with a minimum & inexperienced crew. It's a
safety factor with wind, etc.

The more seperation you can get between talent & the backing, the better.
Not only for reasons of shadows, but to minimize general color pollution.
If you're doing something where you need to capture shadows to key, then
more care needs to be taken placing exposure levels.

Try to stage the action so you aren't seeing the subect from head to toe.
Where talent makes contact with the screen is where you'll always have
problems so avoid that if possible. Similarly, avoid frizzy hair &
transparent objects, or take extra care to light accordingly.

For day exteriors, I'd suggest simply staging the scene so the backing and
talent are evenly lit from the same source, whether that's the sun or
indirect. I'd aslo rig the screen frame with a black solid on the opposite
side of the color so you don't get the sun shining thru the back.

For interior work, I'd rent some Kino-Flo's to light the screen. I recently
had to do an impromptu process shoot with a 20' X 60' screen in a parking
lot at night for a Hi-Def feature. Four, 4 bank X 4' Kinos took care of it
swimmingly. Two of those would be fine for a 12X12.

Oh, adding magenta for back edges really isn't necessary. Used to do that
when doing live Ultimatte green screen work in the early 90's, but with the
current hardware & keying software, it's generally not done these days.
Simply bringing up the luminance level of troublesome edges or hair is all
you need to do.

Hope this helps.

M.


"Dave" <sorry@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:43084db6_1@xxxxxxxxxxxxxxxxxx
> Hi all, I'm about to shoot an instructional video in which the main
> character will be shot on blue/green screen and then keyed over some
> backgrounds. I know the basics and have already done some minor chroma key
> work in the dvcam format, as well as many many jobs using a live switcher
> and studio with full crew (which is easy as everything is always perfect).
> The trouble is this time we are a small crew and will be shooting with an
> eng camera. Plus, the screen has to be on location, outside of a studio
> and
> inside a school building. I am worried about the lighting, as no one in
> this
> small crew will have the necessary specific expertise.
>
>
> Can someone put out a list with all main points and tips, please? For
> example I know about a stronger than usual backlight on the subject, I
> heard
> about the backlight beeing magenta to kill the spill from the blue screen,
> etc. I have doubts about the number of light involved too. For the
> character
> (who will stand and never walk) I plan a classic three lights approach,
> but
> what about the screen?
>
>
> I need help here.
>
>
>
> Thank you to whoever responds :-)))
>
>
>


.

Relevant Pages

  • Re: Johanna Martzy Dvorak DGG 10" LPE 17178 on ebay
    ... high end audio shows, where equipment makers don't care about format. ... Tubes amplification,is in my book,as or more important than vinyl.Is ...
    (rec.music.classical.recordings)
  • Re: HD-DVD vs Blu-Ray - who cares?
    ... that the majority of people, including myself, are waiting for one format - ... VHS / Beta was the introduction of video tape - so people had to pick one ... Even though we all had VHS - the move to DVD was rather quick. ... I dont care, ...
    (alt.tv.tech.hdtv)
  • Re: Tricks to impress Windows users
    ... looks, appearance and format. ... just that I don't care David? ... lowest common denominator. ... A .pdf fixes the document layout and appears identical on any platform. ...
    (uk.comp.sys.mac)
  • Re: OT: Blog-City support even worse than Party Pokers
    ...    Do you think any of us care about your petty problem. ... They showed an example of the correct tags command format. ... So, it not being the tags command wrong, I switched to those category URLs ...
    (rec.gambling.poker)